1. Field of the Invention
This invention relates to washers in general and, more particularly, to dishwashers having an adjustable upper dishrack.
2. Description of the Related Art
A front-loading washer, such as a dishwasher, typically includes a tub having an open front. The tub defines a wash chamber wherein wash items, such as dishes, are cleansed with a wash fluid. The washer is usually provided with a horizontally-pivoting door for closing the open front, and upper and lower dishracks for holding wash items. The upper and lower dishracks are separated by a vertical spacing and are usually movable in and out of the wash chamber so as to permit wash items to be loaded into, or unloaded from, the upper and lower dishracks.
Conventionally, the upper dishrack is provided with wheel assemblies to permit the upper dishrack to move in and out of the wash chamber. The wheel assemblies are attached to opposing sides of the upper dishrack and are carried in tracks secured to opposing side walls of the tub. The wheel assemblies roll along the tracks when the upper dishrack is moved into, or out of, the wash chamber.
Since the height and width of a washer is typically limited by industry standards, it has been found advantageous to enable the vertical spacing between the upper and lower dishracks to be changed so as to maximize the use of available space in the wash chamber. Specifically, it has been found advantageous to be able to change the height or vertical level of the upper dishrack so that large items, such as cookie sheets or tall glasses can be placed in the lower dishrack without contacting the bottom of the upper dishrack. Accordingly, prior art front-loading dishwashers have been developed to provide a vertically-adjustable upper dishrack. Examples of such prior art dishwashers include U.S. Pat. No. 5,474,378 to Smith et al., U.S. Pat. No. 3,736,037 to Doepke, U.S. Pat. No. 3,726,580 to Guth and U.S. Pat. No. 3,726,581 to Doepke, all of which are incorporated herein by reference.
Each of the foregoing references shows a front-loading dishwasher with an upper dishrack supported by four vertically-adjustable support assemblies. The support assemblies each have first and second members slidably interconnected with each other. The first member is attached to the upper dishrack, while the second member is interconnected with a wheel received within a track supported on a side wall of a tub. One of the first and second members is resiliently movable to change the height of the support assembly.
In 037 Doepke, Guth and 581 Doepke, the support assemblies are complicated devices. In each of these references, springs are utilized to make the first or second members resiliently movable, and the first members appear to be welded or otherwise permanently joined to the upper dishrack. In addition, in each of these references, two of the support assemblies are located on each side of the upper dishrack, and are connected together by a control linkage. As can be appreciated, such complicated support assemblies are expensive to manufacture and install. Furthermore, in each of these references, the support assemblies can only be accessed from underneath the upper dishrack.
Smith addresses some of the disadvantages of 037 Doepke, Guth and 581 Doepke. For example, the support assemblies in Smith appear to be relatively inexpensive to manufacture and can be accessed from above the upper dishrack. The support assemblies in Smith, however, require greater operator manipulation to change the height of the upper dishrack than 037 Doepke, Guth and 581 Doepke. In Smith, each one of the support assemblies must be individually manipulated, whereas in 037 Doepke, Guth and 581 Doepke, the support assemblies are manipulated in pairs. In addition, the support assemblies in Smith must be manipulated by an operator when the upper dishrack is both raised and lowered, whereas in 037 Doepke, Guth and 581 Doepke, the support assemblies only need to be manipulated by an operator when the upper dishrack is lowered.
In Smith, there are first and second pairs of adjustable support assemblies respectively attached to opposing sides of the upper dishrack. In each of the support assemblies, the first member is a unitary housing that defines a plurality of vertically aligned slots, and the second member is a flex plate slidably interconnected with the housing. The flex plate has a positioning rib that is received within a first one of the slots in the housing so as to secure the housing from vertical movement relative to the flex plate. A wheel is rotatably secured to the flex plate. The wheel is movably secured within the track secured to the side wall of the tub. In order to move the housing upward or downward, the flex plate must be flexed outward to disengage the positioning rib from the first one of the slots. The positioning rib is then moved into alignment with a second one of the slots. The flex plate is then released to allow the positioning rib to engage the second one of the slots. By manipulating all four of the support assemblies in this manner, the dish rack may be moved between a plurality of vertical positions.
With the Smith support assemblies, an operator will not be able to adjust the height of the upper dishrack in one operation because the operator will need to adjust four separate support assemblies. At most, the operator will only be able to adjust two of the support assemblies at one time.
Based upon the foregoing, there is a need in the art for an adjustable support assembly for an upper dishrack wherein the support assembly is inexpensive to manufacture and install, and permits an operator to adjust the height of the upper dishrack without excessive manipulation. The present invention is directed to such an adjustable support assembly.